Cellulosic composition



Patentedsept. 15,1925; i

' lowing is a specificatio p UNITED STATES EBENEZER EMMET REID, BALTIMORE,

554 3 PATENT 'oFF1c MARYLAND, ASSIGNOR 'IO E. I. DU POINT DE NEMOURS '& COMPANY, OE KVILMINGTON, DELAWARE, A CORPORATION OF.-

.I DELAWARE.

No Drawing.

To all whom it may concern:

Be it known that I, EB NnznR-EMMET Rem, a citizen of the United States and a resident of Baltimore, in the State of Maryland, have invented certain new and useful Cellulosic Compositions, of which the fol- This invention relates to -cellulosiccompositions containing as an essential constituent a neutral butyl phthalate, and has reference more particularly to cellulose nitrate plastics containing. dibu-tyl phthalate.

I or the like, such additions being made for In the practical application of dissolved cellulose and: soluble cellulose compounds,

including cellulose esters, to the various arts and manufactures, such as the production of films, varnishes, filaments, plastic masses, etc., it is customary to blend or mix or otherwise add to the cellulose ester or to its solution, certain non-cell osic materials commonly termedsofteners, camphor substitutes the purpose of imparting to the cellulose or its compounds some desired properties, such as non-inflammability, plasticity under heat, flexibility, etc. These softeners, camphor substitutes and the like, which I shall hereinafter for convenience designate as modi fiers, function in many different ways 1n cellulosic combinations; and the propertles which they impart-to the product depend upon, and are determined by both .the physical and the chemical pro 'erties of the par ticular modifier used.

v or example, if a modifier is non-inflammable, it will impart this property to the cellulose to a degree which is of course dependent upon the character of the modifier and the proportion added; if the modifier is relatively non-vola-- tile its eflect will be more permanent than that of a more volatile modifier; if the modifier is a solvent under suitable conditions for thecellulose material, it will as a rule impart greater flexibility-than if it is a nonsolvent; and particularly, modifiersw'hich i .are liquid at normal temperatures will, other things being equal impart greater flexibility than those which are solid atnor'mal tem-- p'eraturesr v found that the neutral esters of p I have phthalic acid (that is, ortho-phthalic acid) in which at least one of. the alcohol radicals is a butyl group are moresuitable'as modifiers than most substances which have here- 'tofore been proposed for this purpose.

weight 'of' dry hydrogen chloride .is d1s.

cELLuLosIc. comrosrrrolv.

. mists... filed February 4, 1921. 'Serial No. 442, 474.

By the" expression n .11tral butyl phthalates I include not on y a dibutyl phthalate but also the mixed esters such as methyl butyl, ethyl butyl, and propyl butyl, phtha- I 60 above indicatedin which the butyl radical I that of normal butyl' alcohol rather than of .isobutyl alcohol, and specifically, di (norlates. I prefer to use .esters of the kind mal) butyl phthalate. 7 1

The procedure which may be followed to produce the above-mentioned butyl phthalic, .acid esters may be illustrated by the following examples;

' Fro in. phthalic ahkg dflde. v Three parts by weight of phthalic anhydride are added to 3% parts of nor-mal',-

butyl alcohol (B. P. 1-15-117 C.) and the mixture heated" to 117 C. for eight hours.

This completes the first reaction with the" formation of mono-.butyl phthalate which rebonate to remove the mono-butyl phthalate mains dissolved in the excess alcoholj Three I and any free phthalic acid; and finally with water several times until neutral. The dibutyl phthalate is purified from alcohol and dried by passing a current of air through theliquid heated to 160 C. The product is a liquid, odorless, slightly yellow in color and may be obtained water white by distilling under diminished pressure. The .yield is 83.6% of the theoretical. Boilmg point under 29 mm. pressure is 210 Fm). phfihwlic ma."

The use of phthalic acid requires a catalyst for both stages of the-reaction. One part 'by weight of phthalic acid is mixed with 2.5" parts of normal butyl alcohdl solved in the mixture, which'is heated to 117 for twenty-four hours. The Water which formsa's'a lower layer is drawn off from time to time and more hydrogen chloride added toward the. latter part of-the Th nt b ree per ce y heating. The product is washed and purified in the same manner as describedabove.

The yield from phthalic, acid is 79.2% of the theoretical.-.. c I M0' t0-b utyZ phthalate.

Mono-butyl phthalate is obtained as a byproduct from either of the above methods and is recovered by. acidifying the sodium carbonate wash waters. This. can be utilizedin'the preparation of di-butyl phthalate or for the purpose of making mixed esters. It is "a white crystalline solid melting at '73-'14: C., soluble in all the usual organic solvents and in alkali. Recrystallized from acetone or alcohol it is'obtained in large 'rhombic plates. I i

The cellulosic compositions, and particularly the cellulose esters such as the acetate and nitrate, containing a butyl phthalic acid I ester as a modifier have a practical appliso A thirty solution may be prepared dissolving cation in many arts as, for example, in artificial leather, celluloid, lacquers, photographic film,etc. I 4

In preparing the new cellulosic compositions, the butyl phthalicacid ester maybe used in various proportions'depending uponv the result sought, as will be readily understood As one illustrative example of the practice of the invention, I may incorporate parts by. weight of dibutyl phthala'te with 100 parts of cellulose nitrate.

' For producing flexible films,- a suitable cellulose nitrate and dibutyl phthalate in the .ordinary solvents such as ethyl acetate,

benzene, methyl or ethyl alcohol and acetone,

- etc.- Pigments and colors may be incorpo tics, a -suitable amount of a'stabilizer, such as urea. p f f The properties of] di (normal) butyl .rated, and-also, in the production of; plas- .ph'thalate (andiin general of neutral butyl phthalates above described) which -make' it especially valuablein pyroxylin compositions may be listed as follows:

1.. It is a solvent for pyroxylin.

2. It is a liquid at ordinary temperatures and does not crystallize when cooled very much below room temperature, for example to 179 O.

3. It has a very low volatility temperatures. k

4:. It unde'rgoes practically no change on storage either in bulk or-in a pyroxylin film.

5; It is colorless.

at ordinary The neutral butyl phthalates are new substances and are claimed as such in my copending application Ser. No. 428,018 filed December 3, 1920. a t

I claim l; A composition comprising essentially a cellulose ester and, as amodifier therefor, a

neutral butyl pht'halate.

2. A composition comprising essentially a cellulose ester and, as a modifier therefor,

I di-butyl phthalate.

admixture with di (normal) butyl phthaf late. c In testimony whereof I affix my signature.

EBENEZER EMMET REID. 

